The present invention concerns a portable object with a wristband including a keyboard provided with control keys bearing symbols oriented such that they can be read in the direction of the length of the wristband, said keys being distributed over the length of the wristband, a processing unit for data introduced using the keyboard, at least one display device for displaying, in the direction of the length of the wristband, characters introduced using the keyboard and processed by the processing unit, and a power source for the electric power supply of the electronic components of said object. Preferably, the portable object is a wristwatch.
Various portable objects, such as wristwatches, wristbands, alarm signal emitting devices, devices with a compartment for storing accessories or products, or other devices, are usually worn on the wrist by most people. Since these people generally feel the need to know the time wherever they are wristwatches are the most commonly used objects for daily activities.
In addition to the conventional provision of the time and the date, many embodiments of wristwatches have been proposed with additional functional devices, such as for example a calculator, an altimeter, a thermometer or other elements. These additional devices incorporated in said watch provide the advantage of avoiding the need to carry other separate portable devices which are liable to be lost or forgotten.
The use of a calculator combined with a wristwatch may be useful for various professional activities or for leisure when it necessary to calculate for example prices, amounts of bank interest or certain quantities of products. GB Patent No. 1 574 730 discloses an electronic watch provided with such a calculator. In order to do this, the keys of the calculator are arranged on the two strands of the metal wristband close to the watch case so that they can be easily handled by the fingers of the wearer of the watch while figures shown on a digital display complementary to the digital time and date display are visible. All the keys are connected to a central processing unit which is located inside the watch case by a strip of conducting wires passing through the case. A battery is also placed in the wristband for the electric power supply of the calculator.
All the keys have to be close to the watch case to facilitate the use thereof and for a person wearing said watch to check the figures and operations shown on the display. The symbols on the keys are arranged to be able to be readable in a direction equivalent to the reading of the time on the display device given that the calculator is used when the watch is being worn.
The requirement for the keys to be close to the case means that there are only a restricted number of keys to be pressed able to be activated by the user""s fingers. It is thus inconceivable to think of adding a number of keys equivalent for example to an alphanumerical keyboard in a configuration such as presented in this document, or, conversely, by reducing the size of the keys which would make the use thereof inconvenient. Moreover, the electric connection of said keys to a central unit using a strip of numerous conducting wires passing through the case means that the wristband cannot be changed.
Another example of a portable object with a wristband including a calculator is disclosed in Japanese Patent No. 52-0021 120. Several control keys of a calculator keyboard are arranged on one of the wristband strands with the peculiarity of having symbols oriented such that they can be read in the direction of the length of the wristband. When the portable object is placed on a work surface, the display device in the case of the object also allows data introduced via the keyboard to be displayed in the direction of the length of the wristband. All the keys of the keyboard are connected by metal paths to a processing circuit integrated in the case of the object so that the circuit processes the data received to display it on the display device.
A major drawback of this embodiment lies in the fact that a multitude of metal paths have to pass through the case of the object to connect the processing circuit even in the case of a calculator. In the event that the wristband includes computer keyboard keys, the number of metal paths which have to connect the keys to the processing circuit becomes too large, which poses a problem for the connection between the wristband and the case of the object.
Another drawback is that this multitude of paths passing through the case poses watertightness problems and when the wristband is changed, if one wishes to change the type of control keys. The wristband would in this latter case have to be changed by a specialist which is a drawback.
In the same technical context, Japanese Patent No. 56-074765 discloses a wristwatch of the calculator type. The keys of the control keyboard are arranged on the two strands of the wristband on each side of the watch case. In order to facilitate the use of the calculator, control buttons arranged on the watch case allow the direction of display of a display device to be changed.
Since the two strands of the wristband carry keyboard keys, there must be metal paths passing through two opposite sides of the case to connect each key to a processing unit housed in the case which is double drawback. Moreover, another drawback is that in order to change the wristband as a function of a desired type of keyboard, a specialist is required.
An embodiment of a wristwatch with a set of keys bearing figures and letters has been proposed in GB Patent No. 2 254 454. The set of keys forms part of a structure which extends along the arm and which also constitutes the case of said watch. The user of said watch can introduced alphanumerical characters on a liquid crystal display, using the keyboard keys in a direction equivalent to the time indication, i.e. perpendicular to the length of the wristband.
Such a wristwatch has several drawbacks, since it is cumbersome and unattractive, and can be inconvenient for the wearer of the watch, since all the keys have to be accessible and readable while allowing the introduction made on the display to be able to be seen. Since the watch is worn on the wrist when said keyboard is used, a single hand may be used to be able for example to type messages.
One object of the invention is to provide a portable object with a wristband provided with a keyboard with control keys overcoming the aforecited drawbacks of the prior art and which is user friendly and easy to manufacture.
Another object of the invention consists in providing an interface for the transfer of data between the keys placed on the wristband and a processing unit housed in the case of the object which overcomes the drawbacks of the prior art and which does not pose any problem when the wristband is changed.
These objects, in addition to others, are achieved by the aforecited portable object which is characterised in that at least one integrated encoding circuit is placed in the wristband in order to act as a communication interface between the keys of the keyboard and the processing unit which is integrated in a case of the object.
One advantage of the portable object according to the invention consists in that once it is removed from the wrist, it can be placed flat on a suitable work support, the letters and figures marked on each key being oriented in the direction of the length of the wristband, said length of said wristband facing the user, in order for data to be able to be introduced using the keyboard.
The length of the wristband on which the keys of the keyboard are placed, may be equivalent to the dimension occupied by the letters of a conventional computer keyboard. The position of the letter keys corresponds to that of said conventional keyboard to avoid creating any problem of operating the keys by the fingers of a user used to working on a personal computer.
Another advantage of the portable object is that an encoding circuit can be placed on each strand of the wristband. Said circuit receives the information introduced by one or other of the keys and transmits, via a two wire connection to the interface arranged between the wristband and the case, all the data to be processed by a processing unit in order for them to be able to be displayed. The data transmitted to the processing unit on one of the two power supply wires of the integrated encoding circuit are voltage pulses added or subtracted to or from the supply voltage Vdd of said integrated encoding circuit. This encoding circuit thus allows the number of connection wires at the interface between the wristband and the case of the portable object to be limited.
The portable object may be a wristwatch, a wristband with a display device, a device for transmitting alarm signals, a device with a compartment for storing accessories or products or another device having a keyboard with control keys.
Another advantage of the portable object as a wristwatch is that the display of the information introduced by the keyboard occurs in the direction of the length of the watch since the watch is placed on a work surface with the length of the wristband facing the user. If the watch includes a digital display for time functions, the display of said information is thus rotated by 90xc2x0 with respect to the display of the usual time functions when the watch is worn on the wrist. No action on one or other of the keys of the keyboard automatically causes a time function display. Only repeated action on the keys causes the switching between the time display mode and the data entry mode so as to make the information introduced readable.